Mercury is about 5,000 kilometers in diameter; It is, in fact, the smallest planet in the solar system, and even smaller today. A team of experts has discovered that the planet has a slightly smaller radius than previously thought , because the contraction it has suffered in the last 4 billion years has been much more pronounced than experts imagined. This contraction has shrunk its radius by about 7 kilometers.
The images captured by the Messenger space probe (which orbited Mercury in 2011) have been those that have been able to reveal this change in the planet that is closest to the Sun, due to the appearance of faults and ridges in its crust, caused by the cooling and contraction thereof.
The study, which has been published in the journal Nature GeoScience , explains that the images captured by Messenger have a much higher resolution than those captured by the Mariner 10 space probe (which orbited Mercury in 1975) thanks to the use of a capable altimeter laser. to measure your topographic profile.
“Mercury loses heat to space. This cooling of its liquid core causes the reduction of its volume, just as it is easier to remove a ring from a cold finger than from a hot one; Since the surface of this planet is not divided into tectonic plates like on Earth, the only way to respond to this cooling is to push parts of its crust upwards, ”says Paul K. Byrne, lead author of the study and scientist at the Carnegie Institution. of Science.
Crédito imagen: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
